Hi Dave,
I too have a Metacam story that began a few weeks ago.  Our beautiful HEALTHY 9 year old cat, Zoe, started limping 3 days before Thanksgiving.  She refused to put any weight on her front paw.  I waited a day to see if the problem appeared to be healing on its own.  Because it was just before a big holiday and I was not sure if the vet would be open, I took Zoe in to be evaluated.  The vet thought it was a minor sprain and gave me several small viles of Metacam with dosing directions of 0.4 ml every morning on a full stomach for 7 days.  He told me to watch for diarrhea and/or vomiting and to call if any of those problems occurred.  No additional information about the possible side effects of Metacam was offered.  After several days of the medicine, Zoe began to put weight on her paw.  The doctor mentioned that she would begin using the paw while still on the medication because it was an anti-inflammatory and pain killer.  He advised to keep dosing her as the Metacam would mask the problem.  I decided to take Zoe off the medicine after 4 days to see if she continued to use the paw.  While on Metacam, Zoe was VERY lethargic and ate very little.  On day 5 (1 day off medicine) she was sleeping all day and night, barely moving, not eating, and infrequently using the litter box.  On day 6 she stopped using the litter box completely and only got up to drink water, while walking like a 90 year old woman.  I decided that I would take her back to the vet first thing in the morning.  In the meantime, I did an internet search on Metacam to see if the symptoms she was exhibiting were just from her body coming off the medicine.  I was shocked, alarmed, appalled and horrified when I read the countless stories of cats being harmed by Metacam.  I read through the symptoms of Acute Renal Failure (ARF) and Zoe had most of them.  The next morning my fears were confirmed at the vet's office.  Zoe was in ARF.  Her numbers were so high; the vet had difficulty getting a reading to know what her starting point was in order to determine progress. Zoe was transferred to a 24 hour animal hospital and put on IV fluids.  She was unresponsive and at death's door on Saturday.  They have taken VERY good care of her at our local vet hospital.  She is still in the hospital (4 days and counting) and her kidney/liver numbers are improving but she is not out of the woods yet.  They will continue IV's until her blood work is in the normal range and then remove the tubes.  If she maintains the normal levels on her own, then we will have a success story!  We pray that will be the case.
Thank you for your efforts at informing pet owners.  I just wish I had the information BEFORE giving Zoe this drug.  The vet apologized for the "reaction" but said he has had many, many successful outcomes using Metacam.  This was the first case of a cat experiencing ARF.  Fortunately, our vet is paying for Zoe hospital stay.  She has already racked up a $2,000 bill.